Among the important and time-consuming tasks in surgical procedures is the anastomosis or joining of severed blood vessels, and the success of a surgical procedure may depend on the degree of circulation which is restored through such anastomosis. Anastomosing of living vessels is a tedious procedure, particularly in living vessels of small diameter including vessels less than 1.0 mm in diameter. Conventional suturing techniques are time-consuming, extending the duration of an operation.
To aid in anastomosing living vessels, implantable devices which connect severed ends of the blood vessel have been described previously, e.g., U.S. Pat. Nos. 3,254,650, 4,055,186, British Patent Specification No. 1,181,563, German Fed. Rep. Pat. No. 2,101,282 and Nakayama et al., Surgery, December 1962, pp. 918-931.
Even with these devices, anastomosis of small vessels takes longer than is desired. Several of the devices have multiple parts which must be joined together after the vessels have been joined to the individual parts. In most cases, joining vessels together require that the two severed ends of the vessels be held in approximating clamps that hold the vessel ends adjacent to each other for suturing or otherwise joining with the apparatus. Clamping is disadvantageous in that it is time-consuming and tedious to clamp small vessels; it is often difficult to position a clamp in the body; approximating clamps tend to damage vessel tissue; and clamping-anastomosis procedures generally require the combined efforts of at least two surgeons. Also, these prior art systems require difficult and time-consuming manipulations and operations. In many microsurgical applications, a plurality of small blood vessels must be anastomosed, and the combined time of multiple anastomoses adds to the time and expense of performing the surgical operation and reduces the chance of success.
It is a general object of the present invention to provide methods and apparatus which simplify micro-surgical anastomosis techniques, allowing a surgeon to rapidly join a pair of prepared vessels. A further object of the invention is to provide a system to allow microsurgical anastomosis without assistance and without using clamping devices that approximate the vessels.
Herein, an anastomosis ring is provided having at least two and preferably at least three protruding means for hooking the vessels to the ring and an integral tab means by which a surgeon holds and positions the ring as the vessels are being hooked to the ring, the tab means being detachable from the ring after the vessels are anastomosed. The internal diameter of the anastomosis ring is preferably equal to or slightly less than the outside diameter of the vessel, and the outside diameter of the ring is as small as is consistent with the ring having sufficient rigidity to act as the sole support of the two vessels joined thereto. To join a pair of vessels, including a first vessel end having a prepared open end and a second vessel having a prepared opening, the surgeon holds the ring by the tab and draws, e.g., with a forceps, the first vessel end through the ring. Then the surgeon draws the vessel over the end of the ring and a portion of the wall of a vessel over a protruding means so that the protruding means penetrates and hooks the vessel from the outside to the inside. The surgeon continues around the ring, similarly impaling and hooking the wall of the first vessel end on all of the protruding means until the first vessel end is securely hooked to the ring with its end everted and its intima facing outward. The observance of and the manipulation of the vessels over the ring, which is preattached to the tab, is enhanced when the tab is displaced from the plane of the ring, and the surgeon holds the ring with the tab facing the first vessel end. To complete the anastomosis, the surgeon, while using a forceps or the like to hold the ring-attached first vessel by the attached tab, draws, e.g., with a forceps, the second vessel to the ring-attached first vessel and hooks the second vessel on each of the protruding means from the inside out, thereby, apposing the intima of the vessels. The apposed vessels held by the protruding means are slightly stretched, and their natural contractive forces help to provide a fluid-tight seal between the apposed intima.
To assist in joining a pair of vessels to a ring having protruding hooking means, the invention also provides a microsurgical forceps specifically adapted for this purpose. The forceps includes a pair of tangs or arms joined at a base end and a pair of heads or tips which are proportioned to fit through the anastomosis ring and draw the first vessel therethrough. The tips each have a pair of prongs flanking a U-shaped opening, and with the tips pressed together holding a wall portion therebetween, the tips of the forceps are aligned for receiving one of the protruding means between its prongs. Then the forceps is pushed inward to impale the vessel at the location defined by the aligned U-shaped opening. Subsequently, the tips of the forceps can be slid away from the protruding hooking means, leaving the vessel wall impaled thereon.